(Bloomberg) -- Gazprom PJSC has been dealt a blow to access a key pipeline to transport fuel onward from its Baltic Sea Nord Stream link.

Poland won a challenge at a European Union court to annul a European Commission decision that the nation said would boost Gazprom’s ability to use the German Opal gas pipeline.

The EU General Court in Luxembourg on Tuesday overturned the 2016 decision, saying it had been “adopted in breach of the principle of energy solidarity.” The ruling can be appealed.

Opal onshore pipeline connects gas transported by Nord Stream pipeline from Russia to Germany across the Baltic Sea. In 2016, the EU decided to open the previously unused part of the pipeline for competition, allowing Gazprom to keep half of the capacity of the Opal link and use some additional volumes on market conditions. The decision was a “privilege” for the Russian exporter, Poland’s largest gas company PGNiG SA said on the occasion.

According to the decision, the Russian exporter would need to allow other suppliers to use Opal’s capacity under “stringent EU market rules” to ensure non-discriminatory access to all gas companies.

The commission in Brussels didn’t immediately respond to a request for comment.

PGNiG in 2017 had a separate challenge also seeking an annulment of the EU decision rejected as inadmissible and is appealing this ruling.

Gazprom has been seeking full access to the pipeline, which has the capacity to transport 36 billion cubic meters of gas per year. The European Union decision effectively increased the capacity available to Gazprom to 80%, said PGNiG in 2016.

--With assistance from Ewa Krukowska.

To contact the reporters on this story: Stephanie Bodoni in Luxembourg at sbodoni@bloomberg.net;Vanessa Dezem in Frankfurt at vdezem@bloomberg.net

To contact the editors responsible for this story: Reed Landberg at landberg@bloomberg.net, Peter Chapman, Rob Verdonck

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